Endoscopic mucosal resection (EMR) for nodular lesions indicating esophageal adenocarcinoma or high-grade dysplasia followed by ablative therapy, such as radiofrequency ablation, for residual Barrettʼs esophagus (combination therapy) is mainly conducted in Western countries, where the incidence of esophageal adenocarcinoma arising from long-segment Barrettʼs esophagus is high. On the other hand, in Japan, the first choice of treatment for mucosal esophageal adenocarcinoma is endoscopic submucosal dissection (ESD) after identifying the entire margin. In previous reports, the en bloc resection rate and curative resection rate of ESD for esophageal adenocarcinoma were approximately 100% and less than 65%, respectively. These results may be associated with the difficulty in diagnosing the horizontal extent and invasion depth; this is an issue that needs to be resolved. For risk assessment after endoscopic resection, lymphovascular involvement, a poorly differentiated component, and >30 mm in size are risk factors for metastasis. In Western guidelines, lesions without these factors are considered as suitable candidates for curative endoscopic resection. The results from a multicenter retrospective study in Japan supported these criteria. However, further investigation is necessary to establish the criteria for curative resection of esophageal adenocarcinoma.

Guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment published by the Japan Gastroenterological Endoscopy Society in 2012 and guidelines for patients taking anticoagulants additionally published in 2017 include discussions of gastroenterological hemorrhage associated with continuation of antithrombotic therapy, as well as discussions of thromboembolism associated with withdrawal of antithrombotic therapy. In recent studies, the risk of bleeding after gastric endoscopic submucosal dissection remains problematic, especially in patients taking anticoagulants and multiple antithrombotic agents. Patients should be informed of the expected benefits of treatment and the potential complications such as bleeding after gastric endoscopic submucosal dissection.

Background & Aim: The Lugol dye-staining method is useful for detecting squamous cell carcinoma (SCC) and multiple Lugol-voiding lesions (MLVL) in the esophagus. However, it often induces unpleasant side effects. We examined the endoscopic findings on white light imaging (WL) and non-magnifying narrow band imaging (NBI) that can predict the presence of MLVL in the esophagus.

Methods: An endoscopist (T.K.) reviewed the esophageal background mucosa in WL and NBI images from patients with SCC and explored the five endoscopic findings on WL and NBI for predicting MLVL: white protrusions, horizontal lines, low permeability of capillary, brownish area with unclear margin, dot-shaped vessels. Three endoscopists judged the presence of each finding in WL and NBI images of 136 patients with SCC and classified Lugol dye-staining findings to grades A, B and C. We evaluated the sensitivity/specificity for “Grade C” of each finding and various combinations of findings (derivation study). Using the selected finding, they judged another 125 patients with SCC and validated the results (validation study).

Results: In the derivation study, the finding of “horizontal lines or low permeability of capillary” was selected, because the sensitivity /specificity (%) for “Grade C” of 78/47(WL)and 82/43(NBI)were most reasonable. In the validation study, the sensitivity /specificity (%) for “Grade C” was 72/70 (WL)and 78/59(NBI).

Conclusion: The finding of “horizontal lines or low permeability of capillary” on WL and non-magnifying NBI may be able to predict the presence of MLVL in the esophagus. It might be an indication of Lugol dye-staining.

After a 60-year-old woman swallowed a fish bone, she continued to have cervical discomfort. Three days later, she was admitted to our hospital because her symptom did not improve. Computed tomography revealed a high-density linear area in the esophagus, which was judged to be a fish bone. Esophagogastroduodenoscopy revealed esophageal mucosal edema and a fish bone that had become lodged in the esophageal submucosa. After endoscopic mucosal resection and submucosal dissection, the fish bone became visible, and the fish bone could be removed under endoscopy, which obviated the need for surgical procedures. Since we experienced a case of endoscopic removal of a fish bone lodged in the esophageal submucosa, such a procedure may be an alternative as a treatment of foreign body removal from the esophagus.

Case 1 was a 51-year-old man who was referred to our hospital by a local clinic because he had amebic colitis that was resistant to treatment with metronidazole (MNZ). Case 2 was a 53-year-old man who was diagnosed with amebic colitis at our hospital. Both patients received 2 courses of MNZ treatment, but in both patients, ulcers remained in the large intestine on colonoscopy. Following treatment with MNZ, paromomycin (PRM) was orally administered and healing was confirmed by colonoscopy. Residual cysts were considered to be responsible for the resistance to treatment with MNZ in both cases. Based on previous reports and our experiences, we perform colonoscopy 2 to 3 months after completion of MNZ treatment in patients with amebic colitis, and diagnose the patient as having resistance to treatment with MNZ if ulcers remain. It seems better to treat amebic colitis with MNZ and PRM in combination.

A 68-year-old man was referred to our hospital because of watery diarrhea lasting for three months. On colonoscopy, severe luminal stenosis with coarse granular mucosa was observed in the rectosigmoid colon. Based on the findings of imaging and histological examinations, ischemic colitis due to either inferior mesenteric venous occlusion or disordered venous perfusion associated with thrombosis or arteriovenous malformation was suspected. However, Hartmannʼs operation was performed considering the possibility of type 4 colorectal cancer. Histological examination of the resected specimen revealed a small superficial depressed rectal adenocarcinoma accompanied by marked venous invasion with a tumor embolus in the inferior mesenteric vein, that caused long-segmental ischemic change of the rectosigmoid colon. We herein report this unusual case of superficial rectal cancer that required differentiation from ischemic colitis caused by other morbidities.

[Background and aim]　Cold snare polypectomy (CSP) without electrocautery is generally accepted as a less invasive procedure that presents a lower risk of adverse events than hot snare polypectomy. We investigated the safety and usefulness of CSP.

[Methods]　CSP was performed on colonic polyps of 10mm or less, except the pedunculated or depressed type. CSP was performed on 4749 lesions between January 2015 and December 2016 (CSP group). Delayed bleeding rate and the complete resection rate of the cancer cases were compared between lesions that had been treated by CSP and 3891 lesions that had been treated by polypectomy and endoscopic mucosal resection (EMR) (HSP group).

[Results] Patient demographic characteristics including age, gender, and the number, size, and localization of the polyps removed were similar in the two groups. Delayed bleeding was observed in 0.3% of the CSP group which was significantly less than that in the HSP group. Furthermore, in the CSP group, delayed bleeding occurred within only a few days after polypectomy. However, the complete resection rate of the cancer cases in the CSP group was significantly lower than that in the HSP group.

[Conclusions] This study showed that CSP is highly safe, although the complete resection rate of the cancer cases was significantly lower than that in the HSP group. Further studies are needed to evaluate the long-term prognosis of lesions treated with CSP.

The pocket-creation method (PCM) was introduced to overcome technical issues of endoscopic submucosal dissection (ESD) of large subpedunculated tumors. This innovative technique provides several advantages. PCM facilitates the dissection of a thick submucosal layer with minimal mucosal incision, preventing ‘diffuse lift', and provides effective traction and counter-traction as the tip of the ST hood elongates the submucosal tissue and assists dissection. This technique enhances recognition of the muscularis layer and thus a deep dissection is feasible, ensuring a high-quality pathological specimen with an adequate margin. In challenging lesions located on a vertical wall or over a fold, the approach of the knife converts from vertical to tangential by insertion of the tip of the endoscope into the pocket. In addition, having the tip of the endoscope in the pocket provides stability, counteracting any movement due to breathing or heartbeat. In our experience, ESD with PCM is a well-established, useful and safe technique that appears to be an effective alternative to standard ESD.

Benign colonic anastomotic stenosis sometimes occurs after surgical resection of colorectal cancer. In a patient who developed benign colonic anastomotic stenosis after surgical resection of colorectal carcinoma, endoscopic balloon dilation was performed, but the patient developed restenosis and the patientʼs quality of life was poor. This time, we used the ITknife nano^TM to perform endoscopic radial incision and cutting (RIC) which cut down and scraped down the narrowed anastomosis after colorectal carcinoma surgery.

Background and Aim: Colorectal endoscopic submucosal dissection (ESD) remains challenging because of technical difficulties, long procedure time, and high risk of adverse events. To facilitate colorectal ESD, we developed traction-assisted colorectal ESD using a clip and thread (TAC-ESD) and conducted a randomized controlled trial to evaluate its efficacy.

Methods: Patients with superficial colorectal neoplasms (SCN) ≥20 mm were enrolled and randomly assigned to the conventional- ESD group or to the TAC-ESD group. SCN ≤50 mm were treated by two intermediates, and SCN >50 mm were treated by two experts. Primary endpoint was procedure time. Secondary endpoints were TAC-ESD success rate (sustained application of the clip and thread until the end of the procedure), self-completion rate by the intermediates, and adverse events.

Results: Altogether, 42 SCN were analyzed in each ESD group (conventional and TAC). Procedure time (median [range]) for the TAC-ESD group was significantly shorter than that for the conventional- ESDgroup (40 [11-86] min vs 70[30-180] min, respectively; P < 0.0001). Success rate of TAC-ESD was 95% (40/42). The intermediatesʼ self-completion rate was significantly higher for the TAC-ESD group than for the conventional-ESD group (100% [39/ 39] vs 90% [36/40], respectively; P = 0.04). Adverse events included one intraoperative perforation in the conventional-ESD group and one delayed perforation in the TAC-ESD group.

Conclusion: Traction-assisted colorectal endoscopic submucosal dissection reduced the procedure time and increased the self-completion rate by the intermediates (UMIN000018612).